Permanent press fabric resin and processes therefor

ABSTRACT

2,7-dioxo-4,5-dimethyl-decahydropyrimido-(4,5-d)-pyrimidine is reacted with glyoxal and the resulting adduct methylolated with formaldehyde to produce the corresponding methylolated derivative which exhibits very desirable properties as a permanent press resin for fabrics.

Elite Powanda et a1.

PERMANENT PRESS FABRIC RESIN AND PROCESSES THEREFOR Assignee: CelaneseCorporation, New York,

Filed: May 3, 1973 Appl. No.: 357,048

Related US. Application Data Division of Ser. No. 135,778, April 20,1971, Pat. No. 3,753,648.

[15. Cl. 260/67.7, 260/29.4 R, 260/67.6 R, 260/256.4 F Int. Cl. C08g9/26 Feb. 25, 1975 [58] Field of Search 260/67.5, 67.6 C, 67.6 R,260/67.7

[56] References Cited UNlTED STATES PATENTS 3,734,879 5/1973 Von-a eta1. 260/67.6 C X 3,753,648 8/1973 Powanda ct al. 260/67.5 3,764,26310/1973 Powanda et a1 260/69 R X Primary Examiner-Howard E. SchainAttorney, Agent, or FirmJohn A. Sheddcn [57] ABSTRACT2,7-dioxo-4,5-dimethy1-decahydropyrimido-[4,5-d]- pyrimidine is reactedwith glyoxal and the resulting adduct methylolated with formaldehyde toproduce the corresponding methylolated derivative which exhibits verydesirable properties as a permanent press resin for fabrics.

9 Claims, No Drawings PERMANENT PRESS FABRIC RESIN AND PROCESSESTHEREFOR This is a division, of application Ser. No. 135,778, filed Apr.20, 1971, now U.S. Pat. No. 3,753,648.

BACKGROUND OF THE INVENTION In the last decade permanent press fabricshave been a real boon to the textile industry. The future looks evenbrighter as consumers look for permanent press properties in other thancasual wear, shirts and like apparel. It is anticipated, for instance,that use of permanent press resins in household white goods, e.g.,sheets, pillowcases and tablecloths, will account for a substantialamount of the increased demand in the future. To meet this demand theresins must be able to impart permanent press properties withoutdegrading the fiber from which the fabric is made. Typically, the fabricis cellulosic in nature, for example, cotton, cotton-polyester blends,regenerated cellulosic materials, such as rayon, and the like.Degradation can occur, for example, when the resin finish is applied andcured; it may also occur as a result of repeated washings of the treatedfabric using the various popular bleaches and detergents.

The concept of permanent press is twofold: crease resistance and creaseretention. Crease resistance is synonymous with wrinkle resistance andwrinkle recovery, viz., the ability of a treated fabric to resistwrinkling and to retain smoothness of shape and hand upon repeated wearand laundering. Crease retention is synonymous with durable press, viz.,the ability of a treated fabric to drip-dry without loss of crease andto be worn without irnoning.

Clearly, the achievement of all of these desirable properties, andothers such as resistance to soil redeposition, and the like, requireschemicals which are quite special.

Therefore, it is an object of the present invention to provide a novelcomposition of matter which, when applied to a fabric, particularly acellulosic fabric, imparts a colorless, permanent press finish thereto.

Another object is to provide a process for producing a novel compositionof matter which, when applied to a fabric, particularly a cellulosicfabric, imparts a colorless, permanent press finish thereto.

Another object is to provide a permanent press fabric finish.

Yet another object is to provide a process for applying to a fabric, andparticularly to a cellulosic fabric, a permanent press finish.

These and other objects of the present invention, as well as a fullerunderstanding of the advantages thereof, can be had by reference to thefollowing detailed description and claims.

DETAILED DESCRIPTION OF THE INVENTION The above objects are achievedaccording to the present invention by the discovery of novel chemicalcompositions from which useful resins can be readily prepared, thelatter exhibiting, as will be seen hereinafter, permanent presscharacteristics of the type intensely sought after by the textileindustry and hereinbefore briefly described. The novel compounds of thepresent invention are prepared from 2,7-dioxo-4,5-dimethyl-decahydropyrimido-[4,5-d]-pyrimidine, (A), which has thefollowing formula:

2 0H} CH3 HN NH (A) 0 N N o H H by reacting (A) with glyoxal to form thedihydroxyethyl-substituted adduct material, (B), which is repre-. sentedby the following formulae:

H N gfcll HN 3 NH N N HO g and F (B) HO OH which in turn is treated withformaldehyde or source thereof to produce the corresponding methylolatedmaterial, (C), which is represented by the following formula NYN\ 0Y1:cu,

catalysed reaction between acetaldehyde and urea in aqueous menstruum.The ratio of the concentration of CH and 3 acetaldehyde to that of ureain the reaction system is and about 100C., with the atmospheric refluxtemper ature of the reaction system being especially preferred.

It is desirable that the2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrimidine be employedin a high state of purity, i.e., in crystalline form. In addition, it ispreferred that this material be free of color bodies which becomenoticeable when the aminoplast (C) is applied to a fabric, or during thelifetime of the treated fabric.

The compound 2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrimidinesuitable for use in the present invention is conveniently and preferablyprepared according to the following procedure, it being understood, ofcourse, that other methods of synthesis can be used without departingfrom the spirit of the invention. Thus, 5,285 parts by weight (120moles) of acetaldehyde are charged to a suitable conventional reactionvessel and cooled to below 20C. Then a solution of 3,600 parts by weight(60 moles) of urea and 645 parts by weight of reagent grade sulfuricacid (98 percent) in 4,275 parts by weight of water are added dropwisewith stirring to the acetaldehyde. During the addition, a suitablecooling means (e.g., an ice-bath) is applied to the reaction vessel, andthe rate of addition is adjusted, if necessary, in order to maintain thereaction system at a temperature of about 20C. When the addition iscomplete, the reaction mixture is heated to atmospheric refluxtemperature and maintained thereatfor 1 hour. Thereafter, the reactionmixture is cooled to ambient temperature, diluted with water, andfiltered to isolate the crystalline product, (A). The product is washedwith water, then with methanol, and finally recrystallized from water.After drying the recrystallized product at 70C., it weighs 1,467 parts(25 percent of the theroretical yield based on urea) and melts at275-280C. Elemental analysis of the product corresponds to the formula CH N O The material with glyoxal, according to the present invention, asfollows:

semi

cu, ca,

2,7-diox-4,5-dimethyldecahydropyrimido-[4,5-d]pyrimidine, (A), isreacted Theglyoxal/2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrimidineadduct, (B), is then further reacted, according to the presentinvention, by contacting and reacting the adduct with between about 1.0and about 3.0 molar proportions of formaldehyde as illustrated in thefollowing equation:

Eguation II ADDVCT (B) 71HCHo (agony, J"n

HO H

The exact nature of adduct (B) in Equation 1, above, is not known but isbelieved to be a mixture as shown in the equation; likewise,methylolation of the intermediate (B) of Equation I yield what isbelieved to be the 2,7-dioxo-4,5- dimethyl-decahydropyrimido-[4,5-d]-pyrimidine/Glyoxal/HCHO mixture (C) illustrated in Equation 11.

Intermediate (B) is best prepared by reacting equimolar proportions ofglyoxal and (A) in a hydroxylic medium, preferably water, at elevatedtemperatures, e.g., in the range of about 40C. to about 75C, and thenthe reaction is completed by increasing the temperature to atmosphericreflux for a relatively short period of time. Usually, it is best tomaintain the lower temperature for less than about an hour and thenbring the reaction mixture to reflux for about 3 to about minutes. Ofcourse, these temperatures may be varied considerably, depending uponconcentrations of reactions, medium used, and other like factors. Itshould be understood that, in view of the fact that the reactionproceeds rather readily, a wide variety of temperatures, concentrationsand pressures is permissible, the reaction conditions just mentionedbeing those best suited for equimolar proportions of reactants.Obviously, pressures above or below atmospheric require higher or lowertemperatures, respectively; obviously, also, lean or excessconcentrates, below or above stoichiometric, affect the temperaturerequirements for optimum results. In short, the reaction conditions arequite flexible, the stringencies being imposed by desired efficiencies.

Conversion of intermediate (B) to the composition (C) of Equation 11,above, likewise admits ofa wide variety of reaction conditions. Reactionis best carried out in a hydroxylic medium, usually water. Generally,between about 1.0 and about 3.0 molar proportions of formaldehyde,preferably between about 1.90 and about 2.10, is used based on adduct(B). Typical desirable formaldehyde sources are formalin,paraformaldehyde, and the like.

Admixture of adduct (B) with, say, an aqueous solution of formaldehydegive rise to an exotherm. When the exotherm subsides (about 40), themixture of reactants is preferably heated for up to several hours,cooled and pH adjusted to about neutral. Broadly, a temperature aboveabout 40C to about 105C is contemplated herein, the upper temperaturebeing, preferably, no greater than about atmospheric reflux temperature.

As in the case of the Equation 1 reaction described hereinbefore,reaction conditions for the Equation 11 reaction are very flexible, thestringencies also generally being dictated be desired efficiencies. Ifpressures above or below atmospheric are used, proportionately higher orlower temperatures, respectively, are usually indicated; likewise, leanor excess concentrations of formaldehyde with respect to adduct (B)could affect the temperature requirements for optimum results, as wouldof course, the amount of water or other hydroxylic medium used relativeto the reactants.

Fabric treatment is carried out in a conventional pad bath in an aqueousmedium containing the resinforming material (C) and a curing catalyst asthe principal ingredients. Generally, small amounts of surfactant andsoftener are present to enhance transfer of aminoplast material (C) tothe fabric being treated.

The catalyst functions to catalyze the curing process which takesbetween about 5 seconds and about 30 minutes, preferably between about 3minutes and about 15 minutes, at temperatures in the range of about 275Fto about 425F, preferably between about 300F and about 350F. Substancessuitable for catalysing the curing process include any conventionalacidic catalysts or like catalysts heretofore known to be useful incatalysing the curing of conventional aminoplast materials. Such acidcatalysts are employed in conventional amounts, e.g., at a concentrationof between about 1 percent and about 50 percent by weight, based on theweight of aminoplast material. Typical catalysts contemplated herein arethe water-soluble inorganic salts which behave as so-called latent acidcatalysts, e.g., ammonium chloride, magnesium chloride, zinc nitrate,and the like.

According to a preferred mode of carrying out the fabric treatmentprocess of the present invention, the aqueous reaction mixturecontaining the novel composition of matter (C) dissolved therein iscooled to ambient temperature, brought to a pH of about 7.0, andfiltered to remove any insolubles which may be present. Then it isdiluted with water to the desired concentration, mixed with aconventional amount of an acidic curing catalyst, and the fabric to betreated is immersed therein. The amount of resin pickup experienced bythe substrate fabric is determined in large measure by the concentrationof the resin-forming material, (C), in the aqueous pad bath solution.Generally, the concentration of (C) in the pad bath solution (which canbe determined gravimetrically) ranges between about 2 percent or lessand about 65 percent by weight or more, for cellulosic fabrics.Preferably, a pad bath concentration of between about 5 percent andabout 45 percent is used, with a concentration of between 10 percent andabout 25 percent being especially preferred. Percentages are based uponthe total weight of the pad bath solution. The particular desiredconcentration of resin-forming substance in any given instance can beconveniently achieved by appropriate adjustment of the concentrations ofreactants (i.e., (A)/- glyoxal/HCHO) or by the judicious addition ofwater to an initially relatively highly concentrated solution ofresin-forming compound (C).

After saturating the fabric with the pad bath solution, the treatedfabric is withdrawn from the bath, wrung between rollers made of aninert material (e.g., metal, ceramic, rubber, and the like), preferablyrubber rollers or adjacent, cooperatively-functioning stainlesssteel/rubber rollers, dried and simultaneously or subsequently heatcured at a temperature within the aforementioned range. The heat curingstep can, if desired be conducted by contacting the fabric with heatedmetal rollers, preferably heated stainless steel rollers.

In the present invention, the percent pickup of the (A)/Glyoxal/HCHOcomposition is measured as: Wet Pickup, after immersion in the pad bathsolution; Dry Pickup, after curing; Dry Pickup, after I wash; and DryPickup, after 21 washes.

As will be seen hereinafter, all tests are comparative tests usingcommercial resins as controls and comparing these resins with the novelcomposition (C) of the instant discovery. The tests recorded herein,other than resin pickup characteristics, are intended to illustrate theeffectiveness of compound (C) with respect to 7 wrinkle recovery, hand,deterioration of fabric, soil redeposition, and the like. Obviously,permanent press resins are not attractive if they deleteriously affectfiber strength, if wrinkle recovery is poor, etc.

Fabrics, particularly cellulosic fabrics, treated with aminoplastmaterial (C) according to the present invention exhibit as will be seenhereinafter, very desirable and valuable permanent press properties. Theexamples which follow teach the novel adducts (B) and (C) of the instantdiscovery and processes for preparing same. In addition, treatment offabrics with resinforming compound (C) is fully disclosed, as well as anumber of tests comparing the latters efficacy with that of thefollowing commerically popular resinforming compounds:

some --m uca es PERMAFRESH*113B (dimethyloldihydroxyethyleneurea) DMDHEUa 2 m H Cit pfl Z. R hydr oxyalkyl or alkyl] AEROTEX" 8 2 (carbamate)*Trademark for permanent press compound sold by Sun Chemical Co., WoodRiver Junction. R.l.

"Trademark for permanent press compound sold by American Cyauamid Co..Bound Brook, NJ.

DESCRlPTION OF PREFERRED EMBODIMENTS The following examples are merelyintended to be illustrative of certain of the preferred embodimentswithin the spirit and scope of the present invention and,

therefore, are not to be interpreted too restrictively;

parts and percentages given in the examples are by weight, unlessotherwise indicated:

EXAMPLE 1 To a reaction vessel is fed 538 grams of 2,7-dioxo-4,5-dimethyl-decahydropyrimido-[4,5-d]-pyrimidine, 395 grams of 40%glyoxal aqueous solution and water, thus providing a2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrimidine: glyoxalmolar ratio of 1:1. Sufficient water is introduced to obtain goodstirring (approximately 165 grams). The mixture of reactants is heatedto 60C held at that temperature for 45 minutes, and then slowly heatedto atmospheric reflux (103C) and held at that temperature for 5 minutesbefore cooling the reaction mixture to ambient temperature and thenfiltering to remove unreacted 2,-7-dioxo-4,5-dimethyl-decahydropyrimido- [4,5-d]-pyrimidine (147 grams).The filtrate (1,055 grams) therefore contains 395 grams (approximately 2moles) of reacted (A), i.e., the adduct (B), described hereinabove inEquation I, in solution.

EXAMPLE 2 TABLE 1 7vfree Compound Solids pH HCHO Aerotex 82 4812* 6.53.2 Permafresh 113B 45i2* 5.9 O (Al/Glyoxal/HCHO 39 7 O 1.5

Published values EXAMPLE 3 The product (A)/Glyoxal/l-1Cl-1O composition(C) of Example 2, above, is used to treat plain weave white 50/50cotton-polyester (PE) cloth, of the type used in shirts or householdgoods (e.g., sheets and pillowcases). The test procedure is as follows:

Bath: compound tested (dry weight basis) Surfactant (Triton*X-100)Softener (Lubritron**KN) Catalyst-KMMgCl solution)*** Water x rw OCOONOStandard Pad Bath 8(l'71 Wet Pickup Dry at 220F for 12 minutes Cure at325T for 12 minutes 7-97r Dry Pickup After wash Half of the testswatches are laundered through 20 cycles Wrinkle Recovery StiffnessTearing Strength Abrasion Resistance (ASTM D-1175-64T) *Triton X- is atrademark for an alkylaryl polyethcr alcohol surfactant sold by Rohm &Haas Co. Philadelphia. Pa.

Lubriton KN is a trademark for a softener comprised of a nonionieemulsion of a high density olefin sold by Chas. S. Tanner Co.. Warwick,R1

*"Catalyst-KR is a magnesium chloride-based catalyst solution sold bySun Chemical Co, Wood River Junction, R.l.

Procedure:

Tests:

The following table shows the pickup properties of each of the controlsas compared with compound (C), the product of Example 2, above:

Wrinkle recovery characteristics of the fabric of Example 3, above,treated with the compounds of Table 9 II is determined by a well-knownmethod: ASTM D- l 2- 95-67-Warp direction only. The results of thesetests follow:

TABLE III WRINKLE RECOVERY Recovery in Degrees After 20 lnitial WashCycles Blank (Untreated 50/50 PEzCotton) 107 120 Aerotex 82 142 142CONTROLS Permafresh l l3B 145 144 (Al/Glyoxal/HCHO 140 140 Cantileverstiffness of the fabric of Example 3 using the compounds of Table ll isdetermined using the method: ASTM Dl388-64-Warp direction only. Theresults are as follows:

Tearing strength of the fabric of Example 3, above, using the compoundsof Table ll is determined by the method: ASTM D226l-64T-Warp directiononly. The results are as follows:

TABLE V TEARING STRENGTH BY THE TONGUE (SlNGLE RIP) METHOD 4 Break Load(in pounds) After 20 Initial Wash Cycles Blank (Untreated 50/50PEzCotton) 3.14 4.08 Aerotex 3.62 3.69 CONTROLS Permafresh llflB 3.754.]3 (AHGIyoxal/HCHO 3.02 2.97

Conventional soil redeposition tests showed the product of Example 2,i.e., compound (C), to be superior to Permafresh 113B (DMDHEU). Using asmall amount of anti-soil-redposition agent for polyester/cotton blendswhen subjecting the fabric of Example 3, treated as taught in the sameExample, to an otherwise conventional soil redeposition test showed thefabric treated with (A)/Gyloxal/HCHO compound (C) performed as well asthe Aerotex 82 treated fabric and better than the Permafreshll3B-treated fabric under the same conditions. In other words, theAerotex 82- treated fabric and the compound (C)-treated fabric bothremained almost completely white. The anti-soilredeposition agent usedis a water-soluble methyl cellulose derivative (4,000 cps) bearing thetrademark ME- THOCEL90-HG and sold by Dow Chemical Corp., Midland,Michigan. A concentration of 1%, by weight, of Methocel-HG is added tothe conventional soil redeposition test soiling bath alluded tohereinabove; the concentration, viz., 1% by weight, is based on thetotal weight of the soil bath. The use of methyl cellulose derivatives(Methocel) is claimed in copending application Ser. No. 22,140 filedMar. 2, 1970, by A. S. Forschirm et al. and entitled Anti-SoilingPolyester Textile Material.

As is evident from Table III and IV, above, the wrinkle recovery andstiffness performance of compound (C) compares very favorably with theperformance of the commercial resins, even after multiple launderings.This indicates, in the case of wrinkle recovery, good bonding of thecompound (C) resin to the fabric. Tear strength data reported Table V,above, showed compound (C), like the commerical controls, produced nosignificant deterioration in fiber strength. Abrasion resistance tests(ASTM D-ll75-64T) not tabulated hereinabove, likewise indicated nosignificant deterioration in fiber strength.

Pursuant to statutory requirements, there are described above theinvention and what are now considered its best embodiments. It should beunderstood, however, that the invention can be practiced otherwise thanas specifically described, within the scope of the appended claims.

What is claimed is:

1. A method which comprises reacting 2,7-dioxo-4,5-dimethyl-decahydro-pyrimido-[4,5-d]-pyrimidine (A) with glyoxal in ahydroxylic medium to form a dihydroxyethylene-substituted adduct (B),and reacting adduct (B) with between about 1.0 and about 3.0 molarproportions of formaldehyde, the resulting methylolated derivativecomposition (C) being useful as an aminoplast material for impartingpermanent press properties to fabrics.

2. The method of claim 1 wherein the hydroxylic medium is water.

3. The method ofclaim 2 wherein reaction is carried out at elevatedtemperatures.

4. The method of claim 3 wherein the reaction temperature, for the mostpart at a temperature in the range of about 40C to about 75C. isultimately increased to atmospheric reflux temperature to complete thereaction.

5. The method of claim 1 wherein adduct (B) and formaldehyde are reactedin a hydroxylic medium.

6. The method of claim 5 wherein the hydroxylic mey l 1 l2 8. The methodof claim 1 wherein the adduct (B) re- 9. A methylolated (A)/glyoxal/HCHOderivative of action product, without first being separated from its theformulae (C):

' 1 -(cu, we), Hz i ar n o ,N so

CH3 no lg and reaction medium, is reacted with formaldehyde toprowherein n is an integer from 1 to 2, inclusive. duce the methylolatedderivative compound (C).

1. A METHOD WHICH COMPRISES REACTING2,7-DIOXO-4,5DIMETHYL-DECAHYDRO-PYRIMIDO-(4,5-D)-PYRIMIDINE (A) WITHGLYXOAL IN A HYDROXYLIC MEDIUM TO FORM A DIHYDROXYETHYLENESUBSTITUTEDADDUCT (B), AND REACTING ADDUCT (B) WITH BETWEEN ABOUT 1.0 AND ABOUT 3.0MOLAR PROPORTIONS OF FORMALDEHYDE, THE RESULTING METHYLOLATED DERIVATIVECOMPOSITION (C) BEING USEFUL AS AN AMINOPLAST MATERIAL FOR IMPARTINGPERMANENT PRESS PROPERTIES TO FABRICS.
 2. The method of claim 1 whereinthe hydroxylic medium is water.
 3. The method of claim 2 whereinreaction is carried out at elevated temperatures.
 4. The method of claim3 wherein the reaction temperature, for the most part at a temperaturein the range of about 40*C to about 75*C, is ultimately increased toatmospheric reflux temperature to complete the reaction.
 5. The methodof claim 1 wherein adduct (B) and formaldehyde are reacted in ahydroxylic medium.
 6. The method of claim 5 wherein the hydroxylicmedium is water.
 7. The method of claim 6 wherein reaction is made totake place at a temperature in the range of above about 40*C to aboutatmospheric reflux.
 8. The method of claim 1 wherein the adduct (B)reaction product, without first being separated from its reactionmedium, is reacted with formaldehyde to produce the methylolatedderivative compound (C).
 9. A methylolated (A)/glyoxal/HCHO derivativeof the formulae (C):